Tanio Koba GM7 (Colt 1911) - comments?

Maybe someone here has experience with Tanio Koba version of Colt 1911 and could share his opinion?

Personal comments or comparison with an MGC 1911 would be great :-)

Based on YT videos and information from Tanio-san it seems that his model is easier to maintain/clean than MGC thanks to BLK style cartridges.

Claymore posted a short review of this model here:

Hi
Recently looked at importing in the Marushin / Tanio Koba 1911 collaboration, Looks great, BUT Japanese have reported that it has feeding issues, would wait a while till these are sorted out. TK system itself looks great though, and carts are cheap, PLASTIC, but readily available.

Duh, how did I miss existing review?

What I like in this model is that cartridges are not very expensive, and everything seems easy to maintain, as claymore confirms.

Interesting note about feeding issues. Could be cartridge shape, feed ramp shape/angle...
Advantage of having an active company working on that model is hope for ongoing improvements :-)

Reading through various articles and comments the Tanio Koba GM-7 design's only problem lies with the Detonator Pin.

The system is an adaptation of the old MGC Open Cartridge system. Tanio Koba has fitted a rubber / silicone o-ring to the tip of the Det. Pin which ensures a gas-seal within the cartridge once the cap ignites.
The problems start when dirt and residue start to build up on the 0-ring. Just like the original MGC Open Cart. method, the Det.Pin's tip cakes with dirt increasing its diameter.

Feeding and extraction become a problem as the cartridges jam onto the Pin.

The 0-ring can split and tear easily as it's subjected to heat, dirt and high friction levels every time a cartridge is pushed onto it, fires and is then pulled away.
The c.p.HW cartridge design uses an internal piston with 0-ring to achieve gas seal. The 0-ring is only subjected to the action of firing once because every cartridge is a self contained assembly.
Normally each cartridge is fired once, twice at most before thorough cleaning. I'm sure most of us know by now that problems will start with missfires and jams if the cartridges are not cleaned and re lubricated after a maximum of 2, maybe 3 firings.

The Tanio Koba GM-7 design puts a single 0-ring through all the rigours of firing every round in the magazine. 7 shots per mag'
The 0-ring doesn't stand much of a chance under repeated firing.

Attempts have been made to convert Hudson's Grease Gun to use the GM-7 system. The reasoning being sound enough, inexpensive plastic cartridges would give the zinc bolt face a much easier life, but attempts at short or long burst firing with up to 30 rds in the mag' soon had the Det. Pin's 0-ring caked with dirt or split
The last article I read stated that the design would need re-thinking before it could be used successfully in Automatic Sub Machine Guns

That aside, the GM-7 Colt 1911 is a beautifully made, quality modelgun. Make sure you've plenty of spare Det.Pin 0-rings available if you intend firing it

Thank you for detailed writeup Cerwyn, good insight into what happens there.

Dirty detonator is a problem in BLK design, indeed, due to tight tolerances. Too much space and does not blowback correctly, too little and it jams. I did not quite realize about o-ring, it certainly goes through a lot of stress during normal use. Even o-rings in cartridges end their life after so many rounds, so one that has at least 7x more stress is an even larger challenge.

Hi smootik

The following video is worth watching as it shows how the system works. The animated section is particularily good. I can't read Japanese so couldn't tell you if this is a home built conversion or a TKoba made video showing the prototype

https://www.youtube.com/watch?v=ToI4KDQIk_o

The .45 Kimber performs quite well here but notice how often the shooter has to push the slide and fresh cartridge all the way into the chamber.
Based on my experiences with the original MGC Open Cartridge fitted to my MAC11, the 0-ring in this case is dry and getting dirty enough to create friction.
My MAC has an all metal Det.Pin but after 60rds (2 mags) the Pin has enough dirt on it to jam inside a cartridge solid.
A rubber 0-ring wouldn't stand a chance

This next video shows the converted Hudson Grease Gun...

https://www.youtube.com/watch?v=cq7uKBwqANE&feature=related I really liked this idea so wrote to the Gentleman who posted it on youtube. He told me that rapid firing, although looking really good to start with, caused the single 0-ring to split or tear before a full mag could be fired.
This same comment has come from other sources too.

Good find!

The video with Detonics conversion shows conversion steps - very informative. I found using a drilled piston as a tip of detonator pin for converted model very clever, especially that it can be adjusted.

"Push slide forward" is a clear sign of problems in such firing system. When shooting Colt Woodsman I discovered the same issue - sometimes it was detonator pin that got dirty, sometimes walls of the cartridge. When cartridge was pushed into chamber it usually worked ok, as blowback in this model is strong enough to overcome friction. This is metal on metal however, no rubber o-ring to bog things down.

Hi smootik

You'll find this thread interesting too

Note the advice to use yellow boxed MG caps only as they leave less residue

I've had the pleasure of firing Claymore's Tanio Koba 1911 and it worked faultlessly

But I could never get the system working in a full auto SMG due to the o-ring destruction after only a few rounds

8ace

Hi 'ace

How many rounds could be fired before the Colt's Det.Pin needed cleaning Would you say performance was better with the Tanio Koba GM-7 Colt 1911 than other c.p. or PFC systems
There's no doubt Tanio Koba's Colt is a superb modelgun. What is the advantage with it that makes it worth the extra cost
Does it fire better for longer than c.p. or does it all come down to cheap and easy to load / clean cartridges

8ace wrote:

But I could never get the system working in a full auto SMG

So you actually tried to put this system in another modelgun?

I only got a few rounds fired so I didn't really put it through it's paces. The advantages are low cost rounds with only one o-ring to worry about , but the rounds, o-ring and chamber still need cleaning as it has the same dirt build-up from the caps

Theoretically the Tanio Koba det pin could be applied to most of the .45 semi auto modelguns and I assume the extra cost of the model is due to the quality of the model rather than the det pin system.


At the request of another forum member I tried to convert a Hudson Grease gun to the Tanio Koba system. The round cycled through ok but when they were fired it caused a mixture of problems

1: The o-ring only lasted from 1-10 fired rounds
2: Caps can out of the rounds and jammed the bolt
3: Some of the cap plastic melted to the det pin tip

Nothing I could do seemed to ever get it firing well so I decided that it's not designed for SMGs

8ace

Oh, this means no .45 Skorpion, either... ;-)

It is likely that Tanio Koba was aware of the problem and designed system specifically for a pistol, where it works better I wonder if patents for MGC CP cartridges stood in a way of using them in his company.

hi,

I have Tanio Koba GM7, it fires great. One notable thing is, having very few miss fire which is quite common for modelgun.
As every one mentioned, the rounds are cheaper, easy to load a cap because it is open type. Yes, the rubber on det pin is an issue, may be you need to rinse in 50-70 rounds, if you keep firing, you need to replace it in 120-140 rounds. But overall, I find it very well design model. I recommend those who likes to fire a lot.

Also, it is full size, you need no alter to fit the grips from real Colt 1911. I find major drawback will be a mechanics, inside the gun is based on Marui Airsoft, the mechanizm around a sear is different from real one.

But again, this is nice to fire and the appearace is good. It is pity that Tanio Koba do not have militaly 1911.

S

Thank you for your comments shazhib.

Knowing that 50-70 shots is possible before the det. pin 0-ring needs cleaning plus fewer missfires than usual c.p. makes this model very attractive.
Concerns about 0-ring failure may be rather unnecessary in this case.
50-70 shots through a single shot pistol is about the maximum I'd probably manage in one session anyway. A thorough clean down would be done then of both gun and cartridges.
Replacing an 0-ring after 2 or sessions doesn't sound too bad.

The system may not be suitable be for Full Auto use in .45" sub machine guns but it seems well suited to the Colt 1911

Shaz, do you lubricate inside the cartridges or lube the 0-ring before each magazine How is friction overcome with this system

It sound more and more like a good idea to get one. I'm afraid that Colt 1911 prices will only go up due to their 100th anniversary next year.

Colt has an advantage of relatively quick disassembly for cleaning, and with low prices of Tanio Koba cartridges it can be much more fun to shoot 50 rounds in succession, than one or two mags in MGC or Marushin where cartridges are more expensive and not as easy to clean.

What is currently status of production?
I noticed that MEU version seems to be the latest available, released just 3 weeks ago:
http://www.taniokoba.co.jp/MEU/gm7_meu.html

shazhib,
any chance for photos of inside mechanism?

Found this PDF manual, but exploded diagram is not clear enough for me to "see" mechanism.
http://www.taniokoba.co.jp/gm7_img/GM_7manu90415.pdf

Cerwyn,

A material been used for the rounds, amolphas (don't know the correct spelling) nylon, having slipperly in nature, do not really need to lube. Also, when I rinse the rounds after firing, I do not make an inside of rounds in perfect dry, but still it fires.

S

its brilliant for a modelgun, you can put a good few mags through ti beofre jamming due to dirt on the o ring, you can fire as fast as you want without fear of it breaking to pieces a super common fault with the ral size round 45,s its easy to load easy to clean sounds good loud crack like a .22 and throws rounds out cery hards fast and far but as they are light they dont stuffone think you cannot use marushin caps as they fire dirty you can only use mgc caps. itss expensive but worth it if tanio brought out a 9mm or at least another model based on tis system i would buy it, the GM7 looks good feels good and fires great well worth the cash.